1. Field of the Invention
This invention relates to bicycle-type ergometric exercisers and, more particularly, to those having a pedal-actuated wheel and adjustable brakes frictionally engaging the same to move a load indicator in accordance with the energy input by an operator in actuating the wheel.
2. Description of the Prior Art
The most pertinent prior art exerciser is that disclosed in the application for U.S. Letters Pat. Ser. No. 32,242, filed Apr. 20, 1979 and now U.S. Pat. No. 4,291,872, in which the brakes are mounted on a frame pivoted on the wheel support means for movement by the brakes to actuate transducer means to transmit movement of the frame to gauge means for indicating the energy input of an operator in pedal actuation of the wheel. Despite very careful measurements and calculations to determine the proper calibration or face dial graduations of such gauge means for cooperation with its indicating pointer to display the energy being expended at the pedals, it developed from tests made after field use that the indications of energy input to the pedals given by the gauge means did not correspond to the actual energy input to the pedals as determined by dynamometer checks. It had been planned to employ a calibration technique to determine whether any unit was properly calibrated by wrapping a chord around the periphery of the wheel with a free end supporting a ten pound weight and adjusting the brakes or resistance control to prevent the wheel from being rotated by the weight, the unit being considered to be within acceptable calibration if the pointer then indicated a load level between 6.09 and 7.01.
From those tests after field use, plotting of the load indicator settings against pedal energy input produced a slope parallel to the theoretical slope, showing the errors of the gauge indications which were felt to be attributable to failure properly to adjust for minimum friction and subsequent lowering of the friction, as in the wheel and crank bearings, due to use. This also established the inadequacy of the then planned calibration technique because it would have shown that the load indicator was in calibration at the higher settings but had a considerable error at the lower load setting.